1. Field
The disclosed technology relates to a battery pack and a method for minimizing voltage deviations between battery cells of the battery pack.
2. Description of the Related Technology
In general, motor vehicles that derive their power from electromotive force such as electric vehicles, hybrid electric vehicles, and electric scooters require large-capacity batteries capable of outputting high power and correspondingly high voltage and current ranges. The required voltage may be in the range of tens of volts to hundreds of volts and the required current may be in the range of tens of milliamps to hundreds of amps to be able to supply power in the range of several tens of watts to several kilowatts. To meet these requirements, battery packs including a plurality of battery racks are often employed. A battery rack in turn includes a plurality of battery cells that are connected to each other in series and/or parallel to output a desired amount of power.
In order to improve safety, improve the lifetime of the battery pack, and obtain a high voltage output throughout the lifetime of the battery pack, it is desirable to maintain a uniform voltage across the battery cells included in each of the battery racks. To this end, many battery packs have battery management systems for performing cell balancing to minimize voltage deviations between the battery cells.
However, battery management systems are generally designed to monitor voltage deviations between the battery cells and perform voltage balancing at the cell-to-cell level do not address voltage deviations that exist between battery racks nor perform voltage balancing at the rack-to-rack level. Thus, there is a need for a battery pack having a battery rack management system which addresses the cell-to-cell voltage deviations within a battery rack, as well as rack-to-rack voltage deviations within a battery pack.